Hidden hand is the most over hyped perk on any sniper rifle. It only slows down your reticle when your aim is hovering on someone's head. I can tell you that from experience, the majority of the time that hidden hand kicks in, you would not have needed it. It does increase the aim assist by 15% but if you are an experienced sniper then don't bother going for hidden hand. Sometimes, I have been aiming right on my opponent's head and another target runs by, screws up my aim, and I miss the shot. If you like to snipe aggressively then don't bother because it won't help. If you plan on camping and hard scoping then go ahead and choose Hidden hand but if you can reliably land headshots then you do not need it at all.